Moscow came to live with us a couple of weeks ago. He's a 2-year old rescue German Shepherd. He was clearly loved and well cared for by his previous owners and arrived with a large quantity of food, toys and a few medicines. The medicines, prescribed by Moscow's vet, were pancreatic enzymes (for a sensitive tummy) and parasiticides.

I haven't owned a dog before but I am steeped in knowledge about parasiticides through the work Veterinary Prescriber has done on the subject. So for me this is a fascinating exercise in seeing at first hand what happens in practice together with having the point of view of a dog owner.

2 weeks before starting Advocate he had received a dose of Milquantel - milbemycin (endectocide, including roundworm and lungworm) + praziquantel (tapeworm)

At first glance, there's a doubling up on imidacloprid. But now Moscow has a new life, it's time to re-assess his need for parasite control. First, I can't ignore my own principles and beliefs. In general, I don't want to add expose people, animals or the environment to unnecessary chemicals. And I admit I don't like the idea of using regular preventive parasiticides. But I must be realistic and consider the risks of not using parasite control measures.

Fleas first. They're everywhere - on other animals he might encounter (including cats and hedgehogs) and the warming climate means they are more likely to be around all year. I don't want to invite fleas to set up home with us nor subject Moscow to the misery of an infestation. I've never had to deal with dogs and fleas. But I have had a lot of experience with children and head lice. That's tricky enough to tackle and they don't even infest your furnishings and carpets. But if fleas get into your house, it can take months to get rid of them. I don't fancy that. Fleas can also transmit the tapeworm Dipylidium caninum, so stopping fleas prevents that too.

Next, roundworm. Roundworm is more of a problem for humans than for adult dogs. All dogs are likely to carry roundworm and shed it from time to time. and so I need to do what I can to reduce environmental contamination. Of course, I am a diligent picker up of poo and hand washer. But its not certain if roundworm can be transmitted through contact with fur. So regular worming will protect me, my family, and others who come into contact with the dog. As Moscow doesn't hunt (so is unlikely to eat prey carrying roundworm) and there are no young children or other people vulnerable to infection in our household, 3-monthly worming is sufficient.

Ticks? Our house is right next to lovely wooded and farming countryside containing livestock and deer. Great for walks. And we're not far from the New Forest, where Lyme disease-causing Borrelia is endemic. So it's possible Moscow might pick up ticks, although I haven't seen any yet. We're not planning to take Moscow abroad or to areas in the UK where Babesia has been reported. I could rely on checking for ticks, but he's a big hairy dog and it would be easy to miss one. But I'm not certain if a chemical protection with an acaricide or tick repellent is essential. It might be that the flea control I choose also covers ticks.

Tapeworm? Moscow doesn't have raw food, or hunt, or roam on land where he might eat a carcass. Tapeworm control seems unnecessary.

Lungworm (Angiostrongylus vasorum)? This is more tricky to decide about. It's a potentially fatal disease which can develop insidiously. But it is treatable. I've noticed that Moscow eats grass and there are definitely slugs and snails in our garden which would put him at risk if the molluscs in this area are infected. I looked at the Bayer map of reported cases of A.vasorum infection. There has been one unconfirmed case in this town. The IDEXX map tells me there are 20 registered cases in this postal area. It's difficult to know how to use this information, which relies on voluntary reporting, because the absence of reported cases does not mean absence of the parasite. I think I'm going to wait until I've looked at what my options are for preventive therapy overall. It may be that the choice offers protection against lungworm as well as other other parasites

So in summary fleas - yes; roundworm - 3-monthly; ticks - not sure; tapeworm - no; A. vasorum - not sure. The next step is to look at the product options. With over 100 to choose from, this seems a more difficult task than assessing parasite risk. Thank goodness for the Veterinary PrescriberParasiticide Guide! I'll let you know how I've got on with choosing parasiticides next time.